[PATCH 06/14] scsi: sd: Use cached ATA Information VPD page

Martin K. Petersen
2022-03-02T05:36:38Z

Since the ATA Information VPD is now cached at device discovery time it is
no longer necessary to request this page when we configure WRITE SAME.
Instead use the cached information to determine if this disk sits behind a
SCSI-ATA translation layer.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/sd.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2f9d160bc8c2..d6aec12aef76 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3024,8 +3024,7 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
}

if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
- /* too large values might cause issues with arcmsr */
- int vpd_buf_len = 64;
+ struct scsi_vpd *vpd;

sdev->no_report_opcodes = 1;

@@ -3033,8 +3032,11 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
* CODES is unsupported and the device has an ATA
* Information VPD page (SAT).
*/
- if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len))
+ rcu_read_lock();
+ vpd = rcu_dereference(sdev->vpd_pg89);
+ if (vpd)
sdev->no_write_same = 1;
+ rcu_read_unlock();
}

if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
--
2.32.0